I think taking the child away from the parents is a little extreme. The store was across the street. Yes, it was 3 am, but there have been nights that I've forgotten to lock my front door and I'm sure my child could've walked out if they were up. Most children aren't in cribs by 3 years old, and even if they are, they can climb out. It's not like the kid broke a window...someone left a door unlocked!
It's scary that they didn't notice their child was gone, but not unreasonable that they'd be asleep at that hour and not know he was slipping out.
sigh
Minda